I would not doubt the Pens tried to trade Pettersson. He's a bland, redundant, and expensive defenseman on a team that had a bland, redundant, and expensive defense corps. Trading him at this point, though, would be reckless.
People get enamored with players like Smith every year during training camp. He looked great in the 1 game I saw and I've read nothing but good things, but we've seen this before. A guy looks great trying to make the roster and then shows his true level once the grind of the regular season sets in. I'm not saying he won't be good, but it's a risk that I'm not willing to take. Plus, I don't think he pairs well with Petry, so you're probably looking at POJ with Petry. At this point, the Pens would be lucky if POJ ever turned into a player approximating Petts let alone did it this year.
I actually think Petts and Petry will compliment each other pretty well, too. Obviously Petry is going to be doing the heavy lifting, but that's as it should be. No sense in paying him $6.25M to be on the second pairing if he needs a stud next to him.
I could see them continuing the revamp next offseason depending on how things go this season, but I think for better or worse, this is the defense that they will (hopefully) go into the playoffs with (barring major injuries of course). I for one, think it is a big improvement over last year even if it is still not ideal.